Dynamoelectric machines, for example, generators and/or motors, use sealing oil to provide a barrier between an internally contained gas (e.g., hydrogen) and the ambient conditions. In the case of a hydrogen-sealed generator, the sealing oil forms a barrier between the hydrogen and the environment (ambient conditions), thereby retaining hydrogen within the generator. The sealing oil is kept at a slightly higher pressure than the hydrogen in order to prevent leakage of the hydrogen from the machine. When the sealing oil degrades in quality, it is prone to pressure drops, allowing the hydrogen to exit the generator, and the sealing oil to flow into the generator. This form of leakage can require a shutdown of the generator, along with connected power generation equipment (e.g., a turbomachine, motor, etc.), in order to perform maintenance and clean-up.
While many dynamoelectric machines are delivered and installed by a manufacturing and/or selling entity, these turbomachines are frequently managed (over their lifetime) by the customer that purchases the turbomachine. In order to ensure that the sealing oil in the dynamoelectric machine maintains a sufficient quality level to provide an effective seal, the customer conventionally draws a sample of the oil and sends it to a laboratory for testing. However, some customers improperly draw the oil samples, which can compromise accuracy of the testing. Others do not draw samples frequently enough to properly monitor the condition of the oil.
In other cases, sealing oil quality is estimated using empirical data that is tied to an expected lifetime of the oil based upon performance parameters of a dynamoelectric machine. In these cases, a dynamoelectric machine's monitoring system monitors the performance of the machine, e.g., operating speed, hours of operation, shutdown/startup events, etc., and based upon the performance of the machine, estimates a time at which the sealing oil will degrade in quality. These systems do not, however, test the sealing oil to determine its quality.
Due to the deficiencies in the above-noted techniques for monitoring seal oil quality, it is difficult to accurately assess the quality of seal oil in a dynamoelectric machine.